Major 8.7 earthquake strikes off Aceh in Indian Ocean, tsunami warning issued

11th April 2012 - Author: Artemis

A large earthquake has struck in the Indian Ocean off Indonesia’s Aceh province, close to Sumatra. Originally classed at 8.9 it has now been downgraded to 8.7. A tsunami warning for the entire Indian Ocean region has been issued by the Pacific Tsunami Warning Centre. It’s as yet uncertain whether there is a tsunami although it would be due to strike some coastline areas of the region very shortly. We’ll update this article if any tsunami occurs or if the watch is confirmed.

Damage is likely to have occurred in Indonesia as there were reports of ground shaking for up to five minutes from the earthquake. No reports of the scale of damage are yet available.

The location of the earthquake can be seen below.

Update 1:

The USGS has issued a statement saying that the quake had predominantly horizontal displacement rather than vertical. This would generally mean a smaller or perhaps no tsunami. The USGS say they don’t expect a major tsunami from this event.

A magnitude 6.5 aftershock has also struck the same region of the Indian Ocean.

The tsunami warning centre has actually only issued a ‘watch’ rather than a ‘warning’. A watch means a tsunami is possible where as a warning means one is confirmed.

Update 2:

The Pacific Tsunami Warning Centre has confirmed that there likely has been a tsunami. Their latest update says that ‘Sea level readings indicate a tsunami was generated. It may already have been destructive on some coasts’. The tsunami watch remains in effect.

Update 3:

The USGS has reported a huge aftershock of M8.2 in the same area as the initial quake, details here. The tsunami watch remains in place.

Update 4:

Small tsunami waves have been reported in various locations in Indonesia and as far afield as Thailand (1ocm waves) but are unlikely to have caused much damage. The tsunami watch area has been reduced and the watch will likely be removed if no further quakes occur.

This event is unlikely to become a significant insurance loss as the regions which experienced the strongest shaking are largely developing and insurance penetration is low. Now that the tsunami watch is being reduced we won’t update this post unless anything major occurs.